Extend TAG detection distance with MFRC522

[electron67]

Hello everyone, I would appreciate if someone could help me

I'm making a TAG reader with the RFid MFRC522, it works excellent, but I need the TAG to be able to be detected at about 20 cm from the reader, I've tried with different windings and lengths of enameled wire of thin and very thin gauge, different diameters but it continues to detect the TAG when it is 1 cm from the antenna, does anyone have an idea to help me so that the TAG can be detected at 20 cm

Best Regards
Enrique

[electron67]

More variants, I have isolated the original antenna from the reader.

[viktor_au]

Hi
Please try to Google:
Extend range for MFRC522 RFID Reader
https://forum.arduino.cc/t/extend-range ... der/194878

[electron67]

Hi Viktor,

Thanks. . .I appreciate the help, I will try those options, I think the one that would be the right one is the Arduino one, but I am using the PIC16F887; I have been looking for a solution to this on the internet and I think that perhaps an antenna is the solution, but I know that the design of these antennas is complicated, until now a small improvement of 1 or 2 cm more, was to increase the voltage to 4 volts, but I know that the device connected continuously, runs the risk of being damaged.

Thanks
Enrique

[electron67]

As a comment, I am using Flowcode 7 (I think no one watches the Flowcode7 forum) but the version or program works correctly, the problem is how to extend the detection range of the TAG in low (125khZ) or high frequency (13.56 MHz).

I have only tested with 125 khz TAGs, I just ordered some 13.56 MHz TAGs, some comments suggest that high frequency TAGs have a longer range; I will test to see if this is correct. . .

[viktor_au]

Hi Enrique

The --Extend range for the MFRC522 RFID Reader question was asked
by kennethnilsen69 » Thu Apr 14, 2016 11:10 pm
viewtopic.php?t=17471
---
Arduino forum
https://forum.arduino.cc/t/extend-range ... der/194878
Suggests:
Set RFCfgReg to 48db gain. That should get you through an average door.
---
Did you try to:
Set Rx Gain to max?
---
About the antenna.
Probably the MFRC522 uses 1/4 antenna, printed on the pcb as the copper line.
This antenna occupies the 2/3 of the pcb space.
If RF tag uses 13mHz antenna,
If we use dipole, the length of one half would be (appx) 1m.
Total length = 2m.
If we disconnect the pcb antenna and connect the MFRC522 to a huge 2m dipole,
the performance should increase.
The question is:
- do you have space for the dipole?
- do you have an antenna tuner to match the dipole-to-MFRC522 parameters?
Does it worth it?
Please think about it.

[electron67]

Hi Viktor,

Unfortunately I can't use Arduino, I'm using Microchip PIC16F887, and I understand that as I mentioned in the previous post, it is complicated to design an antenna to couple to the reader and requires equipment that we don't have, but maybe someone in the forum had the knowledge or luck to expand the detection range.

In any case, I thank you for the information.

[viktor_au]

Hi Enrique
There is a reason, why MFRC522 has only a few milliwatts in the output.
It was discussed here:
https://www.edaboard.com/threads/rfid-1 ... gn.131000/
You can create more powerfull transmitter and more sensitive reciever,
however some cost is involved and some legal issues.
It is nothing to do with Arduino or Pic.
We are talking now about the (HF) radio frequency issues.
And antennas is a very separate and and complex study.
You need a special tool to measure the antenna impedance.
If you put antenna next to some metal structure, the impedance will change.
You have to tune the antenna again.
Please think about it.

[electron67]

Hi Viktor,

I understand what you're saying... I was looking for a simple solution that might have worked for someone, such as raising the supply voltage, some kind of antenna that would cover a range of a few centimeters, but I see that it is very complicated, RFid was a practical option, it does not require power, it is coded (control of who has access and who to deny); I will look for another option or adapt to what there is.

I appreciate the time you took to help me.
Enrique

[chipfryer27]

Hi

I usually do look in on the "old forums" as do many others, however I'm travelling just now so access is limited.

Viktor offered some good advice that I can't really offer more on, but maybe if you shared why you need the extra range then maybe someone can assist further.

Anti-theft tags have the range you need but look at the antennas (at each side of shop door). As Viktor suggests it may not be practical.

Regards

[electron67]

Hi Chipfryer,

I have a cat that sleeps in a small room in the yard, a typical cat that goes out and comes back, but lately some dangerous animals have come in, snakes, tarantulas, etc. We live outside the city, I thought about setting up a small door which would open when the cat is detected by some sensor, like an IR presence sensor, a ray that when it passes through it the door opens; but any animal with the same dimensions as the cat or that can be detected by the sensor would have access; that's why I thought of an RFID collar, it doesn't require a battery, it's coded, it's the perfect solution, the problem is that the range is 5 cm, practically impossible to be detected in a 50 cm x 50 cm entrance, reducing the door I think with a range of 20 or 30 cm with the TAG inserted in the cat's collar; It would eliminate a large majority of animals that enter the room. I think it is a good solution to my problem, without the problem of recharging batteries, coded so that nothing can open the door and thus have some security for my family with unexpected encounters.

Do you think that an RFID could be fitted? Another advantage is the cost of only 2 USD.

Best Regards

[viktor_au]

Please have a loot at:
https://www.hackster.io/news/diy-pneuma ... 9500bd57b5
https://www.instructables.com/Remote-co ... -for-dogs/
https://www.homemade-circuits.com/elect ... -for-pets/
https://www.instructables.com/Pet-Curfe ... -Pet-Door/

[electron67]

Hi Viktor,

Thank you very much for the links, you have given me more options to try; I was stuck with the idea that only one RFid would serve my purpose; all this time I was looking for how to replace the RFid, with these links I will try some different options.

With everything I have tried and adding some ideas from these links, I hope can to make something functional.

Best Regards
Enrique

[chipfryer27]

Hi

There are differing doors available and I think the "tunnel" type would probably be be better suited, as it contricts the pet's position so may be easier to read any tagging device. You may also be able to wrap many turns of wire around tunnel to assist in detection.

Cats collars typically move around their necks so you cannot always be sure where your tag may actually be positioned, so depending on solution you may need multiple sensors around the entrance to read.

Years ago there was a magnetically operated door that utilised a reed relay. Cat came through the tunnel, and if the magnet attached to the cat's collar was in the correct position, the door opened. You may be able to upgrade that using the Hall effect and some amplification to sense a few inches. Downside is expect all sort of metal things to be stuck to your cat

Of course if your budget allows you could use a Pi, camera and some "face recognition" software to identify your cat <s> That would be cool.

Regards

[electron67]

Hello everyone,

I think the magnet on the collar is a good idea, but you're right, I think that metal dust or small metal pieces would be attracted by the collar, and it would be very uncomfortable for the cat; among the links that Viktor sent there is an option to try, the color sensor, I have not worked with them, I don't know what range they handle, but if you put a red or blue collar it would be a good option, it doesn't require batteries, the problem would be the range of the reader; I'm going to buy a color sensor and I'll do some tests.

I also found a RFid 9 dlls with a range of 18 to 30 cm, it doesn't work with flowcode 10 but I think the reader itself programs the TAGs.

Best Regards

[chipfryer27]

Hi

The colour is a good idea, but I'm not letting my girlfriend hear about this as she will take it as an excuse to spray our cat some funky colour. Probably something glow-in-the-dark coz Halloween is near...

Regards

[electron67]

I started to think that I could paint the cat red, green or blue... something exotic!!!

[chipfryer27]

Hi

Apparantly as long as it is "edible" dye you can paint it pretty much anything you like... but not sure how happy the cat would be though Still as their vision is sifted slightly higher to our own maybe a nice red wouldn't be noticed as much

Regards

[electron67]

HI

It would be a good idea, just the scare it causes at first sight, when they see the cat all red... and walking

A bit of humor, under pressure to find an idea.

Saludos

[chipfryer27]

Hi

I like pointlessly over complicated ideas for simple things as long as the reason for doing so is "because you can"

Regards

[electron67]

Hi, I share your philosophy... I will continue looking for a solution, I will keep you informed of the process.

Best Regards